US2844313A - Ambiguity resolver for a navigation position indicator - Google Patents
Ambiguity resolver for a navigation position indicator Download PDFInfo
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- US2844313A US2844313A US636059A US63605957A US2844313A US 2844313 A US2844313 A US 2844313A US 636059 A US636059 A US 636059A US 63605957 A US63605957 A US 63605957A US 2844313 A US2844313 A US 2844313A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
- G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
- G01S5/12—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial
Definitions
- this invention contemplatesan ambiguity resolver to veliminate any falsevpositionindication of a precision converter. ⁇ by Jcomparing/the'indicated, polar .disstance Lp ofthe aircraftfromthe.centralgroundstatiom which may be a true or'an ambiguous'position, withthe approximate time ⁇ polar .distanceLp .of the aircraft as determined vby an auxiliary systemhaving poor 'accuracy but no ambiguity. When the comparison shows a small difference, the indicated-result Lpcanbe assumed to be a true aircraft position. Any comparisonrdifference in excess of a preselected magnitude -will signal an ambiguous aircraftgposition. In Athe proposed circuitry,-this signal will automatically start the coordinate converter to search for and provide the true aircraft position.
- a vector solver having a nulling loop, an airborne phase meter and a differential network.
- the vector solver is connected to receive the aircraft coordinate analog output from an automatic rectangular coordinate converter in a threestation navigational system.
- the differential network is connected between the vector solver and the airborne phase meter, the latter device providing a reliable but not highly accurate measure of the polar dis- 60 stance Lp' of the aircraft from the central ground station to which the phase meter is referenced and synchronized.
- v:Referring to the ambiguity .resolver schematically 4dis- ..close d rin .the drawing, :a three-.stationanavigational 1sys tern Y. includes a hyperbolici-to-.rectangular coordinate-con- .Verter lvhavingia twop'hasepolarl bearing: Bpfservomotor ...2, the converter yielding .the :aircraft :rectangular f coordinate outputs.Xp,zand :YP in felectricalfanalog form.
- Thegoutputterminals of :the converter'l are connected to the input termina-lsiof 'networksand :'4 by conductors 5 Vand 6,- respectively, 'the commonzoutputi terminal of f the iconverter 1beingconnectedltoaground.
- a stabilizing1voltagetproportional.to the1rate of change of magnetic'iiux in thevectorsolverl is fedback to each -offthe networksfand 4fin i1-conventional manner 'for VSystem stability by .conductorsc1'4 @and 51'5 and the common;input andfoutput terminals ⁇ of the ⁇ vector solver '11 .are-connectedttoaground.
- The'vector'solvernllq has a nulling ;loop 1'6 connected 1 to Fits nulling output f terminal comprising aconductor17:connectedfto1the input of an :amplifier J18A and .a,servomotor119.*connected to ythe amplifier output ⁇ by -a conductor 20,the shaft ⁇ 21fof the servomotor 19sbeing1connected to 'the shaft. of the- Vector solver'l'llso ⁇ :as to :close-.the nulling loop.
- phase meter 24 An approximate but non-ambiguous determination Lp of the polar distance of the aircraft at point P is provided by the phase meter 24 which is referenced to and synchronized with the central ground station.
- the phase meter operates on the principle that the phase displacement between the received signal and the airborne frequency standard is directly proportional to the polar
- the output shaft 25 of the phase meter 24 is operatively connected to displace the potentiometer 26 in direct proportion to the quantity Lp.
- the electrical input side of the potentiometer 26 is connected to an A. C. reference voltage source 27 by a conductor 28, the other terminal of the A. C. voltage source 27 being connected to ground.
- the A. C. output side of the potentiometer 26 containing the information Lp is connected to the other input terminal of differential network 23 by a conductor 29.
- the A. C. output side of differential network 23 is connected to an amplifier 30 by a conductor 31, the common input and output terminal of the amplifier 30 being connected to ground.
- the A. C. output side of amplifier 30 is connected to one side of a half wave rectifier 32 by a conductor 33, the other side of the rectifier being connected to a filter section 34 by a conductor 35.
- the D. C. output side of the filter section 34 is connected to one input terminal of a differential network 36 by a conductor 37.
- the other input terminal of differential network 36 is connected to the positive terminal of a D. C. reference voltage source 38 by a conductor 39 and the negative terminal of voltage source 38 is connected to ground.
- output side of the diierential net- Work 36 is connected to an amplier 40 by a conductor 41, one common input and output terminal of the amplier 40 being connected to ground.
- the output side of amplifier 40 is connected to a diferentialing network 42 by a conductor 43 and the output side of the network 42 is connected to the input terminal of a bistable multivibrator 44 by a conductor 45, one common input and output terminal of the multivibrator 44 being connected to ground.
- the output side of the multivibrator 44 is connected to a solenoid coil 46 of a reversing relay 47 by a conductor 48, the other side of solenoid coil 46 being connected to ground.
- the input pair of power terminals 50a and 50h of the reversing relay 47 are connected to an A. C. line 51a and Slb, the A. C. line being energized by an A. C. source 52.
- the output pair of power terminals 53a and 53b are connected by conductors 54a and S4b to the line phase winding 55 of the two phase Bp servomotor the latter device being' a component of the coordinate converter 1.
- Circuit elements of the ambiguity resolver have selected values so that a predetermined leval of voltage input to the ampliiier 30 will trigger the bi-stable multivibrator 44 and thereby reverse the polarity of its output.
- the resulting reversal of relay 47 will interchange the A. C. leads 54a and S4b to the Bp servomotor 2.
- the impressed voltage upon the amplifier 30 will be governed by the difference between the approximate polar distance Lp' as yield by the -phase meter 24 and the polar distance Lp as yielded by the coordinates Xp and Yp of the accurate coverter 1. Minor diierences between Lp and Lp will not trigger the bi-stable multivibrator.
- any false and ambiguous output of the converter 1 will cause the (Lp-Lp) quantity to exceed the predetermined voltage level and the resulting reversal of line pbase leads to the Bp servomotor 2 will actuate the computer 1 to seek the correct aircraft position.
- An ambiguity resolver comprising a non-ambiguous means for generating in ight the approximate distance from one of three ground stations, au ambiguous means for convertably generating in flight a true distance or an erroneous distance from said one of the three ground stations; said ambiguous means including a two phase polar bearing motor, an A. C. voltage source and a reversing relay connected 4between said A. C. voltage source and the said two phase polar bearing motor; a differential network connected between said ambiguous means and said non-ambiguous means and detection means connected to the said differential network and to the said ambiguous means for converting the output of the said ambiguous means in accordance with the output of said differential network, said reversing relay being controlled by said detection means.
- An ambiguity resolver as claimed in claim 3 wherein the said detection means includes a bi-stable multivibrator driven by said diierential network and controlling the said reversing relay, whereby a voltage output from the differential network in excess of a predetermined tolerance will actuate the relay.
- An ambiguity resolver is claimed in claim 4 wherein said detectingv means includes a rectier connected to the said differential network, a D. C. reference voltage and a second diierential network having connected to its input said rectier and said D. C. reference voltage, the said second differential network having its output connected in controlling relationship to said bi-stable multivibrator.
Description
July 22, 1958 v. H. sELlGER AMBIGUITY RESOLVER FOR A NAVIGATION POSITION INDICATOR Filed Jan. 24, 1957 NM, QR,
Illllll www: EN
-lllllrh- "ull United States Patent O Claims. (Cl. 2359361) 'This invention relates to automatic three-station Vnavigational systemsandparticularly .to anamhiguityresolver nfor automatically l'elirriinting any.falsepositionsolution Thearnbiguity resolver,.contemplatedby.. this invention maybe employed in conjunction with'a three-stationanalog coordinate converter such as disclosed in copend- Iing application SerialNo. `6'l8,264,'filed August`l'2,.l957.
iIn a three-stationdadio-phaseecomparison `navigational system employing three .ground station transmitters to provide Yhyperbolic coordinates of 'therelative aircraft position 'from airborne -receivers 'andpphase comparators, theaircraftposition is `represented l?l".the;1intersection of two hyperbolic curves. Becausebranchesof coplanar hyperbolasfrequently;intersect in twopoints rather than one-point, the planehyperbolic coordinates of a point are frequently insufficient to .provide a unique determination of its position. For this `reason a three-stationgphasecomparison system requirescircuitrrneans tocope with two possible computed. positions of'an aircraft.
YIn general, this invention.contemplatesan ambiguity resolver to veliminate any falsevpositionindication of a precision converter.` by Jcomparing/the'indicated, polar .disstance Lp ofthe aircraftfromthe.centralgroundstatiom which may be a true or'an ambiguous'position, withthe approximate time `polar .distanceLp .of the aircraft as determined vby an auxiliary systemhaving poor 'accuracy but no ambiguity. When the comparison shows a small difference, the indicated-result Lpcanbe assumed to be a true aircraft position. Any comparisonrdifference in excess of a preselected magnitude -will signal an ambiguous aircraftgposition. In Athe proposed circuitry,-this signal will automatically start the coordinate converter to search for and provide the true aircraft position.
As contemplated, there is provided a vector solver having a nulling loop, an airborne phase meter and a differential network. The vector solver is connected to receive the aircraft coordinate analog output from an automatic rectangular coordinate converter in a threestation navigational system. The vector solver yields a solution in accordance with the equation Lp=\/Xp2}-Yp2, 55 where Xp and Yp are either the true or the ambiguous rectangular coordinates of the aircraft. The differential network is connected between the vector solver and the airborne phase meter, the latter device providing a reliable but not highly accurate measure of the polar dis- 60 stance Lp' of the aircraft from the central ground station to which the phase meter is referenced and synchronized. While the drift characteristic in conventional phase meters makes them unsuitable for long time accurate distance determinations, their approximate accuracy is suitable for a yes-no ambiguity resolution. The differences between the computed indication Lp and the approximate but non-ambiguous polar distance Lp' controls a bistable multivibrator Which energizes a reversing relay, the multivibrator changing its output voltage levels when 70 the quantity S exceeds a predetermined acceptable vtolerance. The reversing relay renders the true solution stable distance from the ground station.
ice
and vthe lambiguous -:solution unstable .by `.reversing vthe line-phase leadsgto the two-phase polarbearing Bpfserfvo- Vmotor in the coordinate :.Converter. Suchsreversal v.will .oblige thefconverter'to seek .the1correct intersection of theitwo plane -l-lyperbolicnrvesgaud .rthus yield the true aircraft position.
The features of :the-.invention will be understood more .clearly from the following detailedfdesciiption taken .in iconjunction vwithzthe;taccolrlpanying=: drawing in which:
.The drawing isatschematicrdiagram ofsanambiguity .resolver connected to `ai,three-stationfnavigational `system 'coordinate converter, :the l converter :providingrfrectangu- 1 lar coordinates :from r input 'hyperbolic vcoordinates.
v:Referring to the ambiguity .resolver schematically 4dis- ..close d rin .the drawing, :a three-.stationanavigational =1sys tern Y. includes a hyperbolici-to-.rectangular coordinate-con- .Verter lvhavingia twop'hasepolarl bearing: Bpfservomotor ...2, the converter yielding .the :aircraft :rectangular f coordinate outputs.Xp,zand :YP in felectricalfanalog form.
Thegoutputterminals of :the converter'l are connected to the input termina-lsiof 'networksand :'4 by conductors 5 Vand 6,- respectively, 'the commonzoutputi terminal of f the iconverter 1beingconnectedltoaground. .The outputf'o'f networks3 and- Aare-.connectedg'to the inputs ofamplifiers V7 andy8"byfconductorsf39-anrl';10, trespectively, the -out- .puts of amplifiers7 Panda/8.beingfconnected to a vector .solver 111 by .conductors i12 and'l, .'respectively.
A stabilizing1voltagetproportional.to the1rate of change of magnetic'iiux in thevectorsolverl is fedback to each -offthe networksfand 4fin i1-conventional manner 'for VSystem stability by .conductorsc1'4 @and 51'5 and the common;input andfoutput terminals `of the `vector solver '11 .are-connectedttoaground. 'The'vector'solvernllqhas a nulling ;loop 1'6 connected 1 to Fits nulling output f terminal comprising aconductor17:connectedfto1the input of an :amplifier J18A and .a,servomotor119.*connected to ythe amplifier output `by -a conductor 20,the shaft `21fof the servomotor 19sbeing1connected to 'the shaft. of the- Vector solver'l'llso `:as to :close-.the nulling loop. When the lservomotor 19 :is atl equilibrium, Avoltage appearing from vector .solver output conductor 22 to ground i's'deteri mined by the formula rpm/Leaving, when, LIJ isrhe computed polar distance of the aircraftfatgpointP. .The 4conductor 22 is connected to one 'inpuftfterminal of a dierential network l25, i n
An approximate but non-ambiguous determination Lp of the polar distance of the aircraft at point P is provided by the phase meter 24 which is referenced to and synchronized with the central ground station. The phase meter operates on the principle that the phase displacement between the received signal and the airborne frequency standard is directly proportional to the polar The output shaft 25 of the phase meter 24 is operatively connected to displace the potentiometer 26 in direct proportion to the quantity Lp. The electrical input side of the potentiometer 26 is connected to an A. C. reference voltage source 27 by a conductor 28, the other terminal of the A. C. voltage source 27 being connected to ground. The A. C. output side of the potentiometer 26 containing the information Lp is connected to the other input terminal of differential network 23 by a conductor 29.
The A. C. output side of differential network 23 is connected to an amplifier 30 by a conductor 31, the common input and output terminal of the amplifier 30 being connected to ground. The A. C. output side of amplifier 30 is connected to one side of a half wave rectifier 32 by a conductor 33, the other side of the rectifier being connected to a filter section 34 by a conductor 35. The D. C. output side of the filter section 34 is connected to one input terminal of a differential network 36 by a conductor 37. The other input terminal of differential network 36 is connected to the positive terminal of a D. C. reference voltage source 38 by a conductor 39 and the negative terminal of voltage source 38 is connected to ground. The D. C. output side of the diierential net- Work 36 is connected to an amplier 40 by a conductor 41, one common input and output terminal of the amplier 40 being connected to ground. The output side of amplifier 40 is connected to a diferentialing network 42 by a conductor 43 and the output side of the network 42 is connected to the input terminal of a bistable multivibrator 44 by a conductor 45, one common input and output terminal of the multivibrator 44 being connected to ground. The output side of the multivibrator 44 is connected to a solenoid coil 46 of a reversing relay 47 by a conductor 48, the other side of solenoid coil 46 being connected to ground. The input pair of power terminals 50a and 50h of the reversing relay 47 are connected to an A. C. line 51a and Slb, the A. C. line being energized by an A. C. source 52. The output pair of power terminals 53a and 53b are connected by conductors 54a and S4b to the line phase winding 55 of the two phase Bp servomotor the latter device being' a component of the coordinate converter 1.
Circuit elements of the ambiguity resolver have selected values so that a predetermined leval of voltage input to the ampliiier 30 will trigger the bi-stable multivibrator 44 and thereby reverse the polarity of its output. The resulting reversal of relay 47 will interchange the A. C. leads 54a and S4b to the Bp servomotor 2. The impressed voltage upon the amplifier 30 will be governed by the difference between the approximate polar distance Lp' as yield by the -phase meter 24 and the polar distance Lp as yielded by the coordinates Xp and Yp of the accurate coverter 1. Minor diierences between Lp and Lp will not trigger the bi-stable multivibrator. However, any false and ambiguous output of the converter 1 will cause the (Lp-Lp) quantity to exceed the predetermined voltage level and the resulting reversal of line pbase leads to the Bp servomotor 2 will actuate the computer 1 to seek the correct aircraft position.
It is to be understood that various modifications of the invention other than those above described may be effected by persons skilled in the art without departing from the principle and scope of the invention as defined in the appended claims.
What is claimed is:
1. An ambiguity resolver comprising a non-ambiguous means for generating in ight the approximate distance from one of three ground stations, au ambiguous means for convertably generating in flight a true distance or an erroneous distance from said one of the three ground stations; said ambiguous means including a two phase polar bearing motor, an A. C. voltage source and a reversing relay connected 4between said A. C. voltage source and the said two phase polar bearing motor; a differential network connected between said ambiguous means and said non-ambiguous means and detection means connected to the said differential network and to the said ambiguous means for converting the output of the said ambiguous means in accordance with the output of said differential network, said reversing relay being controlled by said detection means.
2. An ambiguity resolver as claimed in claim 1 wherein said non-ambiguous generating means includes a phase meter. Y
3. An ambiguity resolver as claimed in claim 2 wherein the said ambiguous generating means includes a vector solver for determining the computation quantity Lp in accordance with the formula Lp=\/X"+l7,2 said vector solver being adapted to receive the quantities Xp and Yp and said vector solver being connected to the said dilerential network, wherein Xp and Yp are the rectangular coordinates of a ght position P, the origin of the coordinate system is at the said one of the three stations and Lp is the polar distance from the coordinate origin to the ight position P.
4. An ambiguity resolver as claimed in claim 3 wherein the said detection means includes a bi-stable multivibrator driven by said diierential network and controlling the said reversing relay, whereby a voltage output from the differential network in excess of a predetermined tolerance will actuate the relay.
5. An ambiguity resolver is claimed in claim 4 wherein said detectingv means includes a rectier connected to the said differential network, a D. C. reference voltage and a second diierential network having connected to its input said rectier and said D. C. reference voltage, the said second differential network having its output connected in controlling relationship to said bi-stable multivibrator.
References Cited in the le of this patent UNITED STATES PATENTS 2,472,129 Streeter June 7, 1949
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US636059A US2844313A (en) | 1957-01-24 | 1957-01-24 | Ambiguity resolver for a navigation position indicator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US636059A US2844313A (en) | 1957-01-24 | 1957-01-24 | Ambiguity resolver for a navigation position indicator |
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| Publication Number | Publication Date |
|---|---|
| US2844313A true US2844313A (en) | 1958-07-22 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US636059A Expired - Lifetime US2844313A (en) | 1957-01-24 | 1957-01-24 | Ambiguity resolver for a navigation position indicator |
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| US (1) | US2844313A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2989233A (en) * | 1958-10-29 | 1961-06-20 | Sperry Rand Corp | Rhumbline course and distance computer |
| US3002691A (en) * | 1957-08-12 | 1961-10-03 | Sperry Rand Corp Ford Instr Co | Analog converter |
| US3217146A (en) * | 1960-09-30 | 1965-11-09 | Wesley A Fails | Navigation coordinate presentation computer |
| US3296423A (en) * | 1961-06-30 | 1967-01-03 | Gordon E Ewertz | Average bearing rate computer and semi-automatic plotter |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2472129A (en) * | 1943-08-04 | 1949-06-07 | Sperry Corp | Radio navigation system |
-
1957
- 1957-01-24 US US636059A patent/US2844313A/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2472129A (en) * | 1943-08-04 | 1949-06-07 | Sperry Corp | Radio navigation system |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3002691A (en) * | 1957-08-12 | 1961-10-03 | Sperry Rand Corp Ford Instr Co | Analog converter |
| US2989233A (en) * | 1958-10-29 | 1961-06-20 | Sperry Rand Corp | Rhumbline course and distance computer |
| US3217146A (en) * | 1960-09-30 | 1965-11-09 | Wesley A Fails | Navigation coordinate presentation computer |
| US3296423A (en) * | 1961-06-30 | 1967-01-03 | Gordon E Ewertz | Average bearing rate computer and semi-automatic plotter |
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